Babies and young children, as well as animals, can die from heatstroke when left unattended in a closed vehicle at high environmental temperatures (this applies equally to any living, breathing being that does not have the ability or cognition to open a vehicle door when it gets too hot). The driver, be it parent, grandparent, family member, friend or caregiver, either may forget that there is a baby asleep in the back seat or may intentionally leave a sleeping baby or dog alone in the back seat to run a “short” errand. Vehicular heatstroke may also occur when a child is playing in a locked, unattended vehicle.
On average, 37 children die each year from heatstroke when left unattended in a closed vehicle (Null, J., “Heatstroke Deaths of Children in Vehicles”, Department of Meteorology and Climate Science, San Jose State University, http://noheatstroke.org (Dec. 1, 2016)). Guard and Gallagher reported that heat-related deaths in young children in motor vehicles occur each year, throughout the country, and primarily during the summer months (Guard, A., & Gallagher, S. S., “Heat Related Deaths to Young Children in Parked Cars: an Analysis of 171 Fatalities in the United States, 1995-2002”, Injury Prevention. 11, 33-37 (2005)). Further, there have been 700 reported U.S. child vehicular heatstroke deaths during the 19-year time period from 1998 through October, 2016 (Null, 2016). Null also reported that nearly 75% of the deaths were children ages 2 years or less.
The internal temperature of a car can reach dangerous temperatures within minutes, even on a mild sunny day (Nixdorf-Miller, A., Hunsake, D. M., & Hunsaker III, J C., “Hypothermia and Hyperthermia Medicolegal Investigation of Morbidity and Mortality from Exposure to Environmental Temperature Extremes”, Arch Pathol Lab Med. 130, 1297-1304 (2006)). For example, on a warm, sunny day, the greenhouse effect rapidly heats the air inside a closed vehicle to temperatures well in excess of the 104° F. (40° C.) life-threatening, core human-body temperature. At this point, severe hyperthermia resulting in heatstroke occurs, causing the baby or young child to die. Moreover, these preventable deaths have even occurred on days when the temperature was less than 51° F. (Null, 2015).
McLaren, Null and Quinn (2005) described three phases of heat illness (McLaren, C., Null J., & Quinn, J. “Heat Stress form Enclosed Vehicles: Moderate Ambient Temperatures Cause Significant Temperature Rise in Enclosed Vehicles”, Pediatrics, 116(1), e109-e112 (2005)). The mildest form is heat stress, which is physical discomfort and physiologic strain. McLaren et al. (2005) next describe heat exhaustion which they define as a “mild to moderate illness associated with dehydration and a core temperature ranging from 37-40° C.” (98.6-104° F.). Symptoms of heat exhaustion include: intense thirst, weakness, anxiety, dizziness, fainting and headache (McLaren et al. 2005). The authors describe the third phase as heatstroke. Heatstroke occurs when the core body temperature is greater than 40° C. (104° F.); the child is no longer able to regulate body temperature (Nixdorf-Miller et al., 2006). At this stage, there are changes in the central nervous system, which results in delirium, convulsions, coma, and death (McLaren et al. 2005). In addition, babies and very young children are more at risk for hyperthermia (core body temperature greater than 40° C.) because of their limited thermoregulatory response to excessive heat (Nixdorf-Miller et al., 2006).
Sunlight and the greenhouse effect are responsible for heating the interior of vehicles. When sunlight passes through the windshield and windows of a closed vehicle, the sunlight heats the air and objects (e.g., dashboard, steering wheel, seat cushions, etc.) inside the vehicle (Nave, R., “Greenhouse Effect”, Department of Physics and Astronomy, Georgia State University, http://hyperphysics.phy-astr.gsu.eduhbase/thermo/grnhse.html (2015)). These objects, in-turn, radiate heat in all directions in the infrared (IR) portion of the electromagnetic spectrum. IR radiation has difficulty passing through glass and, consequently, is reflected back inside the vehicle causing the temperature in the vehicle to rise further (Nave, 2015). Furthermore, water vapor and CO2 in the air within the car absorbs this IR energy and traps the heat inside the vehicle (UCSB ScienceLine, “Why is the inside of a car hotter than the outdoor temperature on a sunny summer day?”, University of California, Santa Barbara, http://scienceline.ucsb.edu/getkey.php?key=3882 (2015). This trapping of IR radiant energy, also known as the greenhouse effect, rapidly heats the air inside the closed vehicle. The interior temperatures may easily surpass the 104° F. life-threatening, core human-body temperature. If there is an unattended child in a closed vehicle, severe hyperthermia resulting in heatstroke occurs and the child dies.
As shown in McLaren et al., 2015, at page 111, the temperature rise due to the greenhouse effect is a nonlinear function of elapsed time, with two-thirds of the rise occurring within the first 20 minutes. Regardless of the original ambient temperature, each car showed a similar rate of increase. Thus, “even at relatively cool ambient temperatures, the temperature rise in vehicles is significant on clear, sunny days and puts infants at risk for hyperthermia” (McLaren et al., 2015). The Stanford University study also observed an 80% temperature increase within the first 30 minutes with maximum internal temperatures at 60 minutes (McLaren et al., 2015). The results of the Stanford group correlates with documentation of heat-related deaths by Null (2015). Documented cases of child heatstroke deaths occurred where the ambient temperature was as low as 51° F. (Null, 2015); two children died in a high altitude sunny climate when the outdoor temperature was merely 35° F. (Null, 2015).
The issue of children dying of heatstroke when left unattended in closed vehicles has captured the attention of the U.S. Department of Transportation's (DOT) National Highway Transportation and Safety Administration (NHTSA). In July 2012, NHTSA published a detailed evaluation of products designed to prevent children up to 3 years of age from being left behind in closed vehicles—a scenario leading to heatstroke (Arbogast, K. B., Belwadi, A., & Allison, M., “Reducing the Potential for Heatstroke to Children in Parked Motor Vehicles: Evaluation of Reminder Technology”, Report No. DOT HS 811 632, Washington, D.C.: National Highway Traffic Safety Administration). The 2012 NHTSA study evaluated reminder technology devices and found these devices to be inconsistent and unreliable in performance (Arbogast, Belwadi & Allison).
Since 2012, NHTSA has sponsored annual “Where's Baby? Look Before You Lock” awareness campaigns during warm-weather months to alert parents and others to the dangers of heatstroke (http://www.acf.hhs.gov). On Jul. 31, 2015, NHTSA joined Safe Kids Worldwide as part of National Heatstroke Prevention Day to “urge parents and caregivers to take proper precautions to prevent child heatstroke tragedies in hot vehicles (www.nhtsa.gov).”
In addition, NHTSA released a new technical report in July, 2015 providing a functional assessment of both add-on and integrated unattended child reminder systems (Rudd, R., Prasad. A., Weston, D., & Wietholter, K., “Functional Assessment of Unattended Child Reminder Systems”, Report No. DOT HS 812 187, Washington, D.C.: National Highway Traffic Safety Administration). The 2015 NHTSA study found these devices to function as expected (Rudd, Prasad, Weston & Wietholter). However, these devices are only effective if they are properly used, installed, and activated by the caregiver. In addition, they require the caregiver to take appropriate action to prevent a tragedy. Meanwhile, every year, children continue to die from vehicular heatstroke, even with educational awareness programs and available reminder systems.
Previous solution attempts to address the problem of leaving an unattended child in a closed vehicle have included: awareness campaigns, sponsored by both government and private sector safety stakeholders, and devices aimed at reminding the driver that a child has been left behind in the vehicle. Thus, prior solution attempts include mainly educational and technological warning solutions.
Educational campaigns have been actively promoting awareness of the dangers of leaving unattended children in vehicles. Unfortunately, they have not been especially effective. Awareness campaigns include the 2012 NHTSA's “Where's Baby? Look Before You Lock” annual campaign (www.acf.hhs.gov) and the 2015 Safe Kids Worldwide “Childhood Injury Prevention Convention (www.safekids.org).” While promoting awareness is important, it is by no means fail-safe. Unfortunately, children continue to die from heatstroke each year. According to research performed by Jan Null (2016) of San Jose State University, the number of U.S. child vehicular heatstroke deaths has not decreased since 2012. In 2011, there were 33 vehicular heatstroke deaths. Since 2012, when education programs were initiated, there has been an average of 34.5 deaths per year. In order to tackle this problem more effectively, additional solutions must be implemented in conjunction with parent or caregiver education.
In recent years, numerous devices have appeared in the marketplace to help remind the driver/caregiver that a child is present in the backseat of the vehicle. These devices differ in the technologies employed. Several approaches have been proposed in recent years to remind the driver that he/she has left a sleeping baby in the vehicle. Examples include (1) a baby seat equipped with a sensor in the seat harness that triggers a series of tones when the ignition is switched off and the baby is still buckled in the seat, (2) a clip that is attached to the strap on the baby seat which senses when the driver leaves the vehicle without the baby and then communicates an alert to an app on the driver's smartphone, and (3) sounding an alarm when the vehicle key fob leaves the proximity of the vehicle. A shortcoming of all of the above approaches is that they are all interactive, requiring action on the part of the driver, and, in the case where the baby is intentionally left so the driver can run a “short” errand, the approaches are completely ineffective. In addition, current available devices cannot help children at play who are trapped inside an unattended vehicle.
In July 2012, NHTSA evaluated 18 devices that would potentially prevent heatstroke in children left unattended in vehicles. This study was done in conjunction with Center for Injury Research and Prevention at the Children's Hospital of Philadelphia, Pa. NHTSA published Reducing the Potential for Heat Stroke to Children in Parked Motor Vehicles: Evaluation of Reminder Technology, thus providing objective systematic evaluation of products available on the market (Arbogast, Belwadi, & Allison).
The 2012 NHTSA study identified and categorized, based on technology, 18 heatstroke prevention devices. Eleven of the 18 devices were commercially available. Of these, only three devices were chosen to be evaluated because they “had technology that sensed the presence of a child in a child restraint (Arbogast, Belwadi, & Allison).” These three devices included: Deluxe Padded Safety Seat Alarm System (or Suddenly Safe Pressure Pad manufactured by Suddenly Safe “N” Secure Systems Inc., Bensalem, Pa.), the ChildMinder Smart Pad (manufactured by Baby Alert International, Dallas, Tex.) and the ChildMinder Smart Clip (manufactured by Baby Alert International, Dallas, Tex.). A comparison of the product features is listed in Table 1.
TABLE 1Product Features of Unattended Child Reminder Devices (NHTSA 2012)Suddenly Safe PressureChildMinder SmartChildMinder SmartTypePadPadClipLocation of SensorPressure pad in car seatPressure pad in car seatBuckled chest clip on(Sensing Parameter)(1 sensor)(5 sensors)harness of car seatNotification SourceKey fobKey fobKey fobActivation of SystemActive -Active -Active -Driver turns switch toBase unit beeps whenSafety Clip beeps whensyncing position, holdschild is seated tobuckled to alert driverit adjacent to sensingindicate driver toto activate system andpad to activatesynchronize fob tosynchronize key fobactivate systemNotification MethodAlarm sounds, key fobAlarm soundsAlarm soundsvibratesRange6 to 50 ft15 ft15 ftPower SourceBatteriesBatteriesBatteriesVehicle InterfaceNoneNoneNone
The sensing parameter in both the Suddenly Safe Pressure Pad and the ChildMinder Smart Pad is a pressure/force in the child restraint. The sensing parameter in the ChildMinder Smart Clip is a buckled chest clip on the child restraint. Each device was evaluated when the child was first positioned in a parked vehicle. The devices were retested following a 25-minute commute. Both device activation and care giver notification were recorded.
These devices all operated as intended. Each product was designed to identify the presence of a child in an unattended vehicle. Each one required activation at the time the child was placed in the child restraint. The Suddenly Safe Pressure Pad required the driver to activate the system upon placing the child in the car seat. Thus, it was possible to use the car seat without activating the safety features. This problem was avoided with the ChildMinder Smart Pad and the ChildMinder Smart Clip, as the unit would beep until the key fob was synchronized with the transmitter. All three of these devices are presently on the market.
NHTSA researchers concluded that the tested devices were inconsistent and unreliable in their performance. The children often needed to be repositioned within their child restraints in order for the pressure sensors to detect their presence. In addition, there was difficulty with synchronizing communication between the sensors and the key fobs.
Additional problems with these products include human error from improper installation, and the need to have functioning batteries. The key fob would also need to be present on all sets of keys designated for that vehicle. In addition, placement of the pressure pad in the car seat would need to be adjusted as the child grows in order for the sensors to detect the presence of a child. Caregivers could potentially have a false sense of security.
A major drawback with these devices, however, is they all serve to simply remind the driver that a baby or young child is present in the car, and, as discussed above, such a reminder is ineffective when the driver is aware that a baby or young child is present in the car and does nothing to actually prevent heatstroke from occurring or if the caregiver is unaware that a child is inside the car.
Additional devices to avoid heatstroke mortality in unattended children left in vehicles have become available since the 2012 NHTSA study. In July 2015, NHTSA published “Functional Assessment of Unattended Child Reminder Systems (Rudd, Prasad, Weston & Wietholter).” These car seat systems included both add-on and integrated systems that alert the driver/caregiver to the presence of a child in the vehicle.
The evaluation procedure studied car seat products designed for newborns and children up to the age of three who use harness-based child restraint car seats. Six commercially available car seat products were tested using standardized, anthropomorphic test devices (crash dummies) as surrogates for newborn, 1 and 3 year old children. The six car seat products included: the Aviso Child-in-Car Alert, ChildMinder Elite Pad System, ChildMinder SoftClip, Forget Me Not, Suddenly Safe ‘N’ Secure Wireless Child Protection System, and the True Fit I-Alert C685. A comparison of the product features is listed in Table 2.
TABLE 2Product Features of Unattended Child Reminder Devices (NHTSA 2015)SuddenlySafe ‘N’SecureForget MeWirelessChildMinderNotChildAviso Child-Elite PadChildMinder(SunshineProtectionTrue Fit I-Typein-Car AlertSystemSoftClipBaby)SystemAlert C685PresenceDirectDirectIndirectDirectDirectDirectDetection(flexible(pressure(buckled(pressure(pressure(pressure(Sensingsensing strip)pad)chest clip onpad)pad)pad)Parameter)harness)NotificationVehicleKey fobKey fobSmartphoneKey fobSmartphoneSourceSurroundingsor Key fobemailActivation ofAutomaticManual -Manual -Manual -Manual -Automatic -SystemDriverSafety ClipSmartphone:DriverApp does notAutomaticpressesbeeps whendriver slidesneed to beManualbutton onbuckled toactivates app switch onopened for(usertransmitteralert driverKey fob:fob tosystem toactivation)totosynchronizesactivatework. Carsynchronizesynchronizewithsystemseat containsfob andfob andtransmitteraccelerometeractivateactivateto detect carsystemsystemin motion andpressuresensor todetect carseat occupiedNotificationMountedAlarmAlarmSmartphone:AlarmSmartphone:Methodspeakerssounds,sounds,Messagesounds, keyAudible tone,within carLEDs flashLEDs flashdisplay &fob vibratesscreenand car hornon fobon fobaudible tonemessage,Key fob:vibrationaudiblealarmPower Source12 V CarBatteriesBatteriesKey fob:BatteriesRemovableBatterybatteriesRechargeableSmartphone:BatterychargedbatteryCurrentYesYesYesYesYesNoAvailability
The Aviso Child-in-Car Alert is an add-on system that interfaces with the vehicle's power and horn. A sensing strip is placed under the car seat fabric cover. This sensing strip flexes under the weight of the child, thus detecting the child's presence. The sensing strip is connected to a control module mounted to the vehicle's interior. The control module includes electrical connections to the vehicle's 12V power and horn. The Aviso requires vehicle-level installation. It is compatible with most types of car seats, but is not compatible with detachable infant carriers. The Aviso notification system is activated as soon as the vehicle power is shut off. If the child is left unattended in the vehicle, a second alert in initiated at a fixed delayed time of 9 minutes and 25 seconds. The car horn will notify bystanders that there is a child in the vehicle. However, dangerous life threatening temperatures can occur earlier than 9.5 minutes. According to McLaren, Null and Quinn (2005), in the journal Pediatrics, the interior vehicular temperature can reach 106° F. within 10 minutes.
The ChildMinder Elite Pad System, Forget Me Not, and Suddenly Safe ‘N’ Secure Wireless Child Protection System are all add-on systems that rely on a fob for delivering notifications to the user. A pad is placed under the car seat fabric cover in order to detect the weight of a child. The pad is connected to a transmitter module, which is placed on the outer shell of the car seat. The transmitter module and fob use replaceable batteries. These systems do not provide an end-of-trip notification. During testing, NHTSA researchers recorded variability in the ChildMinder Elite Pad System. In addition, the Forget Me Not add-on system has a second version which relies on a user's smartphone for Bluetooth notification delivery. A specialized app must be installed and running on the smartphone. A problem with this system is that the specialized app must be installed and running on the smartphone of all possible drivers or caregivers. In addition, the app must be activated at the time of use. NHTSA found this product to be reliable with reproducible results when tested. However, NHTSA did not take into account realistic issues that involve proper and effective use by the caregiver. These include factors such as the app being installed on each of the individual phones of each caregiver for that child, and the caregiver being in actual possession of his/her phone person with a charged and functioning battery with the phone and Bluetooth turned on. In addition, this device requires the caregiver to take appropriate action in response to the notification, and is not effective for the caregiver who leaves the child intentionally in order to run a quick errand. Furthermore, this system is useless in the case of children who accidently get locked in vehicles during play, when the caregiver is unaware that a child is in the vehicle.
The ChildMinder SoftClip is an add-on system which relies on a fob for notification delivery. A retrofit chest clip replaces the original car seat chest clip of the car seat harness; this chest clip contains a transmitter and closure switch. The chest clip transmitter module and fob both use replaceable batteries. The ChildMinder SoftClip and Elite Pad System remain activated whenever a child is buckled into an infant car seat, even when the infant carrier is not installed in the car seat base within the vehicle.
The True Fit I-Alert C685 is a convertible car seat with an integrated car seat monitor which relies on a user's smartphone for notification delivery. The car seat shell incorporates a control module and two switches that detect the weight of a child. The control module contains a rechargeable battery that must be removed from the car seat for charging. The system relies on a Bluetooth connection with the smartphone. A specialized app must be installed on the smartphone, which will function automatically. However, it would be necessary for all caregivers of this child to install the app on their phones. (The manufacturer is no longer producing this product anymore.)
NHTSA reviewed six different unattended child reminder systems. Overall, these products generally functioned as expected. These products focused on children aged three or younger who could potentially be victims of heatstroke. These systems also rely on the driver/caregiver to respond to the device and return to the vehicle for the child. The majority of systems also require correct installation and positioning of pressure sensors. In addition, these pressure sensor pads must be readjusted as the child continues to grow. Lastly, most of these systems require manual activation in order to be used.
Since the 2015 publication from NHTSA, additional devices have come on the market to prevent children from being unattended in vehicles. Most of these are apps which require smartphones. These include: Kars4kids Safety App, Don't Forget Your Baby App, Baby Reminder (I&E Applications) and Precious Cargo App. A new product using pressure sensor pads in the car seat (Drivers Little Helper App) interacts with a smartphone and is similar to the systems evaluated by NHTSA. The NFC Baby in Car Reminder sticks to the phone cradle in your car and automatically activates the app. Once activated, the app sends you a notification upon removing your phone from the cradle. These apps are subject to the same problems previously described with devices that use smartphones.
In July 2015, Evenflo, a car seat manufacturer, launched a new car seat, the Advanced Embrace DLX with SensorSafe with reminder technology built within the child restraint. The chest clip contains a sensor which is connected to a transmitter within the car seat. The “system does not require Bluetooth, cellular or other devices” (www.evenflo.com/SensorSafe). The car seat plugs into the OBD II port. The battery lasts six years and emits a low battery alarm.
Currently, there are many available products on the market to remind caregivers not to leave young children and babies unattended in a vehicle, thereby reducing the potential for heatstroke. All of these devices are reminder systems and rely on proper use, installation and activation by the caregiver. In addition, all these products require timely action and intervention on the part of the driver/caregiver to prevent a tragedy.
Furthermore, reminder devices are completely ineffective in preventing a potential tragedy in situations where the child has intentionally been left in the vehicle so the driver can run a “short” errand, or where the child at play gets locked in a vehicle. There are no available systems that address this problem. In addition, the reminder devices function only for those caregivers who have purchased and installed them. An optimal system would be a passive system installed in all cars manufactured in the future.
There is a need for a Vehicular Heatstroke Prevention System (VHPS), “The Heat-Free Car Life Saver,” that would not only identify a child left unattended in a vehicle, but also detect high temperatures that could endanger the child, while having the ability to automatically lower the temperature and alert the caregiver and/or emergency personnel.
Thus, although there are many products available on the market to address heatstroke prevention, they are all reminder systems and rely on proper use, installation, and action on the part of the caregiver. There are no products or devices that prevent severe dehydration, organ failure and death in children left unattended in a vehicle.
It is desirable to have a vehicular heatstroke prevention system which will detect the presence of a child, automatically lower the vehicular cabin temperature, and notify a caregiver and/or emergency personnel.